Here is the full list of all 36 Somniphobia achievements.
Get rid of the Cat monster.
Get rid of the Puppet monster
Get rid of the Producer monster
Get rid of the Ghost monster
Get rid of the Oxon monster
Get rid of the Villin monster
Get jump scared by the Producer without eyes!
Get jump scared by Oxon without eyes!
Complete the whole game
Play the secret raycast mini game.
Look at those lovely poppies.
See the Producer in the red room.
See Oxon in the red room.
Play this game after 10pm.
Play this game at 3am.
Play this game on two consecutive days.
Play this game on four consecutive days.
Play this game on seven consecutive days.
Play this game on fourteen consecutive days.
Make Susan go to sleep for a sixth time, so that she sleeps on the weekend.
Get the good ending where Susan doesn't die.